WHILE EXTREME CARE HAS BEEN IMPLEMENTED IN THE
PREPARATION OF THIS SELF-HELP DOCUMENT, THE AUTHOR AND/OR PROVIDERS
OF THIS DOCUMENT ASSUMES NO RESPONSIBILITY FOR ERRORS OR OMISSIONS,
NOR IS ANY LIABILITY ASSUMED FROM THE USE OF THE INFORMATION,
CONTAINED IN THIS DOCUMENT, BY THE AUTHOR and / OR PROVIDER.
You will need...
1. A 3 wire cable that is routed between switch box 1 and switch box
2 - these wire cables comes with a black / red / white wire plus the
bare equipment grounding wire.
2. A 4 wire cable that is routed between switch box 2 and switch box
3 - these wire cables comes with a black / red / blue (or white
striped) / white wire plus the bare equipment grounding wire.
3. A 2 wire cable that is routed between switch box 1 and the
fixture box - this wire cable comes with a black / white wire plus
the bare equipment grounding wire.
4. A circuit power supply source wire cable that is routed to switch
2.
5. Insulated wire nuts to connect / join wire together, variety of
sizes out there so make sure you obtain the correct size.
6. Wire staples, to affix the wire cables to wall studs as needed.
Wire cable must be secured within 6 inches of entering the
electrical box.
7. Wire cable / wire strippers.
8. Screwdrivers as required.
Holes drilled to feed wires through studs must be 1 1/4" from edge
of stud, in instances where the wire cable is closer then the edge
of stud must have a 1/16-in. thick protective metal plate over the
area where the cable is being feed through (may want to notch the
stud so that that the protective plate does not create a bump on the
drywall). Also read the article called '
Wire
Routing Basics'
Wire cables entering the electrical box - secure the cable clamp at
the box snug enough that the cable cannot come out but not too tight
as to pinch the cable and break through the insulated cover of the
cable.
You must have at least 6 inch length of wire inside the electrical
box, it can be a bit more but not less, it can fail an inspection if
the length of each wire is less than 6 inches. Also read the article
called '
Box
Fill Calculations' as there is a limit on how many
wires are allowed for a certain size electrical box.
STEP 1 - Make
certain that the power supply cable is dead - turn off the
electrical breaker at the service panel. Make certain that everyone
in the house is aware of what you are doing so that they do not get
the notion to reset the breaker when another light in the home is
not working.
STEP 2 - Make the
box openings (if a existing home)
STEP 3 - Feed /
Route the wire cables.
STEP 4 - Mount / Install the Electrical Boxes (make sure the
electrical boxes are secured as some fixtures are heavy and may
require additional support) [The electrical box should not extend
beyond the edge of the finished wall or ceiling so that the fixture
can mount flush to the ceiling and the wall switch cover will mount
flush - but it also should not be recessed too far into the wall or
ceiling]; then feed the wire cables into the electrical boxes.
Sometimes because of tight openings in existing homes, the wire
cable may to be feed into the electrical box then the box put in
position and secured.
STEP 5 - Connect
the wires...
Connections
Instructions:
(as depicted in the diagrams above)
At the Fixture box...
One cable entering this box, coming from switch 1.
* a) connect the black wire coming from switch 1 to the switched
ungrounded conductor (hot) of fixture (shown as black in picture) -
if the fixture has screw type connections then connect to brass
color screw.
* b) connect the white wire coming from switch 1 to the grounded
conductor (neutral) of fixture (shown as white in picture) - if the
fixture has screw type connections then connect to the silver color
screw.
* c) please see under important notes in regards to the equipment
grounding conductor (bare wire).
At switch 1 box...
Two cables entering this box, one coming from switch 2, and one
coming from the fixture
* a) connect the black wire coming from fixture to common screw of
switch 1.
* b) using an insulated wire nut connect / join the white wire
coming from fixture + the white wire coming from switch 2.
* c) connect the red wire coming from switch 2 to the one of the
remaining main screws of switch 1.
* d) connect the black wire coming from switch 2 to the last
remaining main screw of switch 1.
* e) please see under important notes in regards to the equipment
grounding conductor (bare wire).
At switch 2 box...
Three cables entering this box, one cable coming from switch 1 and
one cable coming from switch 3, and one cable coming from the
'circuit power supply cable'.
* a) using an insulated wire nut connect / join the white wire
coming from switch 1 + the white wire coming from switch 3 + the
white wire from 'circuit power supply cable'.
* b) using an insulated wire nut connect / join the black wire
coming from switch 3 + the black wire coming from 'circuit power
supply cable'.
* c) connect the red wire coming from switch 1 to the one screw that
is a matching pair of screws on switch 2 (both the red and black
wires coming from switch 1 must go to a matching pair of screws at
switch 2)
* d) connect the black wire coming from switch 1 to the 2nd screw
that is a matching pair of screws on switch 2 (both the red and
black wires coming from switch 1 must go to a matching pair of
screws at switch 2)
*e) connect the red wire coming from switch 3 to one screw from a
different matching pair of screws. (both the red and blue wires
coming from switch 3 must go to a matching pair of screws at switch
2)
*f) connect the blue wire coming from switch 3 to the 2nd screw that
is a matching pair. (both the red and blue wires coming from switch
3 must go to a matching pair of screws at switch 2)
***Just to clarify further - The red
and black wires coming from switch 1 go to one set of matching
screws at switch 2 -- The red and blue wires coming from switch 3 go
to a different set of matching screws at switch 2 - A matching set
is 2 screws of the same color.***
* g) please see under important notes in regards to the equipment
grounding conductor (bare wire).
At switch 3 box...
One cable entering this box coming from switch 2 (wire cable # 3).
* a) connect the black wire coming from switch 2 to the common screw
of switch 3.
* b) connect the red wire coming from switch 2 to one of the
remaining main screws of switch 3.
* c) connect the blue wire coming from switch 2 to the last
remaining main screw of switch 3.
* d) using an insulated wire nut cap off the white wire.
* e) please see under important notes in regards to the equipment
grounding conductor (bare wire).
Important Notes:
By electrical codes you MUST have at least 6 inches of wire in the
electrical box itself, and also the wire must be able to reach at
least 3 inches outside the box, it can fail an electrical inspection
if the required min. wire length is not met. You may have the wires
a bit longer (within reason) but they cannot be shorter. Also see
the note on box fill further down in this article.
If the fixture has screw type connectors, the ungrounded conductor
(hot) is connected to the brass color screw, and the grounded
conductor (neutral) is connected to the silver color screw. If it
has black and white wires coming from fixture, then just connect
black to black and white to white. Use wire nuts of the correct size
to join wires together.
The wire cable running between switch 1 and switch 2 has 3 wires in
it - red / black / white (plus the bare equipment grounding wire).
The wire cable between switch 2 and 3 has 4 wires in it - black /
red / blue / white (plus the bare equipment grounding wire).
What is not shown in the drawings to avoid confusion, is that each
wire cable also has a bare equipment grounding wire included. This
wire is connected to a grounding screw in each electrical box (if
the box is metal), joined either through the grounding screws in the
box itself or via a wire nut to the bare wire of the next cable
entering / exiting the box, it is also connected to any grounding
screw (if there is one) on the switch itself, as well as any
grounding screw at the fixture (green wires that attach to the
fixture are grounds). Now if using a plastic box, it is made of a
material that is non conductive, however some plastic boxes have a
metal strip inside that can still be used to connect equipment
grounding wires, in the event that it does not use wire nuts to join
the bare grounding wires together. The equipment grounding wire
(bare in most cables) must be electrical conductively joined
throughout the circuit. Green wires are also equipment grounding
conductors.
At the 3 way switches (switch 1 & 3) there are 3 main electrical
screws, one of these 3 screws is distinctly different in color
(perhaps darker) than the other 2. This screw connection is called
the common screw. It is very important that in order for all the
switches to work as they are intended to that the correct wire is
attached to the common screw. Basically as depicted in the drawings
one switch has the ungrounded conductor (hot) from the circuit power
supply cable attached to the common screw, where the other switch
had the ungrounded conductor (hot) feed to the light fixture itself.
Please also note that there are a variety of manufactures out there
that make 3 way switches so it is possible that the switch you buy
may have the common screw located in a different spot or side of the
switch then depicted in the drawings in this article, just make sure
that the wire depicted to go to the common screw of each of the
switches is actually connected to the common screw of the 3 way
switch you bought. The other 2 wires going between the remaining
screws of one switch to the other switch does not matter as long as
one wire of the 2 remaining wires go on each of the remaining 2
screws of the switch.
At the 4 way switch (switch # 2) there are 2 sets of matching
screws, one set will match in color and the other set will be
distinctly different perhaps darker in color, it is important that
the traveler wires from the previous switch are connected to one
matching set, and the traveler wires going to the next switch are
connected to a different matching set.
If there is an equipment grounding screw on the 3 way or 4 way
switch it may be green in color and be separated away from the main
connections of the switch and likely part of the metal frame that is
also part of the mounting structure of the switch.
Extensions to this Switch
circuit...
Be Aware that there is a limit by code on how many wires can be in a
given size electrical box, when adding more wires to the same box
you may have to install a larger and / or deeper box to allow space
for more wires coming and out of the box.
Here is an article / explanation in regards to box fill calculations
'
Box
Fill Calculation'
The instructions here are based on the fact that the circuit has
already been wired to the configuration shown in this article and we
are now making the wiring changes for onward power.
From the fixture location...
Only switched onward power is available from the fixture location.
Onward switched power...
(example more than one light fixture controlled by the same
switches)
(showing bellow the fixture portion of the circuit)
Not shown in the diagram but the onward
cable also has a bare wire (equipment grounding conductor) that
also must be connected to all the other bare wires at the
fixture electrical box.
Connection Instructions for
onward cable (switched)
* a) Using an insulated wire nut, connect / join - the black
wire coming from switch 1 + the black wire connected to the
switched ungrounded conductor (hot) of fixture + the black wire
of onward cable.
* b) Using an insulated wire nut, connect / join - the white
wire coming from switch 1 + the white wire connecting to the
grounded conductor (neutral) of fixture + the white wire of
onward cable.
Identification of wires in
onward cable....
Black - Switched ungrounded conductor (hot - switched)
White - Grounded conductor (neutral)
***************
From the switch locations....
Switch 1 options...
Only onward switched power is available at the switch 1
location.
Onward switched power...
Not shown in the diagram but the onward
cable also has a bare wire (equipment grounding conductor) that
also must be connected to all the other bare wires at the switch
electrical box.
Connection Instructions for
onward cable (switched)
* a) Using an insulated wire nut, connect / join - the black
wire coming from fixture + the black wire connected to common
screw of switch 1 + the black wire of onward cable.
* b) Using an insulated wire nut, connect / join - the white
wire from fixture + white wire coming from switch 2 + the white
wire of onward cable.
Identification of wires in
onward cable....
Black - Switched ungrounded conductor (hot - switched)
White - Grounded conductor (neutral)
**************
Switch 2 Options:
Only 'always on' power is available from the switch 2 location
Onward always on power...
Not shown in the diagram but the onward
cable also has a bare wire (equipment grounding conductor) that
also must be connected to all the other bare wires at the switch
electrical box.
Connection Instructions for
onward cable (always on)
* a) Using an insulated wire nut, connect / join - the black
wire from 'circuit power supply cable' + the black wire of
onward cable + the black wire coming from switch 3.
* b) Using an insulated wire nut, connect / join - the white
wire coming from 'circuit power supply cable' + the white wire
of onward cable + the white wire coming from switch 1 + the
white wire from switch 3.
Identification of wires in
onward cable....
Black - Ungrounded conductor (hot - always on)
White - Grounded conductor (neutral)
***************
Switch 3 Options:
Only 'always on' power is available from the switch 3 location
Onward always on power...
Not shown in the diagram but the
onward cable also has a bare wire (equipment grounding
conductor) that also must be connected to all the other
bare wires at the switch electrical box.
Connection
Instructions for onward cable (always on)
* a) Using an insulated wire nut, connect / join - the
black wire coming from switch 2 + the black wire of
onward cable + the black wire connected to common screw
of switch 3.
* b) Using an insulated wire nut, connect / join - the
white wire coming from switch 2 + white wire of onward
cable.
Identification of wires in onward cable....
Black - Ungrounded conductor (hot - always on)
White - Grounded conductor (neutral)
Foreign Users:
The colors of the wires
depicted are based on the standards and code
requirements / configuration in the United States and
Canada. If you are viewing this site from a foreign
country, your wiring standards and color of wires may be
different but the principal and sequence of wiring will
still remain the same. Therefore the information in this
article may still be of use to you regardless of what
country you may be in. Just translate the colors used
here to the color of wires used in your country in
regards to ungrounded (hot) conductors / grounded
conductors (neutral) and equipment grounding conductors
as well know applicable code requirements in your
country.
